For the slightly more OCD of us (unless I'm a blind caveman and this somehow exists already): 1) Add the ability to move collections around on the list through simple drag and drop. It seems it's possible to drag and drop collections, but it does absolutely nothing. (+ maybe add good old alphabetical ordering option?) 2) Some kind of multi-select feature to be able to drag and drop multiple wallpapers. My browser didn't agree with my automatic reflex to hold down Ctrl.
Would make it far easier to rearrange things when your favourites list is starting to grow fast. If I'm just potato and this can already be done, please tell.